I think I found the answer!!! I think it may be a Killdeer. I looked it up on the internet and the picture looks like the ones in my back yard.
Yes, I believe you are right. I have one in my yard and looked it up and came up with a Killdeer as well.
I would love to know the answer to this too. Last year and again this year one has nested directly in the grass. Last year it screamed and flew at my husband when he tried to mow the grass. He mowed around it so as not to bother the eggs. This year it seemed to remember that he wouldn't bother it, because he mows closer to it while still not bothering the bird or eggs, and it hasn't tried to attack him this year. I mean, what kind of bird would nest in the grass?